package com.cheng.example.juc;

/*
 * 生产者和消费者案例,优化，防止出现虚假唤醒，线程无法停止
 */
public class TestProductorAndConsumer {
    public static void main(String[] args) {
        Clerk clerk=new Clerk();

        Productor pro=new Productor(clerk);
        Consumer cus=new Consumer(clerk);

        new Thread(pro,"生产者 A").start();
        new Thread(cus,"消费者 B").start();
        new Thread(pro,"生产者 C").start();
        new Thread(cus,"消费者 D").start();
    }
}

//店员 假如只有一个商品位置
class Clerk{
    private int product=0;

    //进货
    public synchronized void get(){
        while(product>=1){//为了避免虚假唤醒问题，应该总是使用在循环中
            System.out.println("产品已满！");
            try{
                this.wait();
            }catch(InterruptedException e){
            }
        }
        System.out.println(Thread.currentThread().getName()+" : "+ ++product);
        this.notifyAll();
    }

    //卖货
    public synchronized void sale(){
        while(product<=0){
            System.out.println("缺货！");
            try {
                this.wait();
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        }
        System.out.println(Thread.currentThread().getName()+" : "+ --product);
        this.notifyAll();
    }
}

//生产者
class Productor implements Runnable{
    private Clerk clerk;
    public Productor(Clerk clerk){
        this.clerk=clerk;
    }
    @Override
    public void run() {
        for(int i=0;i<20;i++){
            try{
                Thread.sleep(200);
            }catch(InterruptedException e){
            }
            clerk.get();
        }
    }
}

//消费者
class Consumer implements Runnable{
    private Clerk clerk;
    public Consumer(Clerk clerk){
        this.clerk=clerk;
    }
    @Override
    public void run() {
        for(int i=0;i<20;i++){
            clerk.sale();
        }
    }
}
